Screening and drying apparatus.



.N. M. ROSENDAHL.

SCREENING AND DRYING APPARATUS.

APPLICATION FILED JULY 28.1913.

1,212,264. I Patented Jan. 16,1917.

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N. M. ROSENDAHL.

SCREENING AND DRYING APPARATUS.

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SCREENING AND DRYING APPARATUS.

APPLICATION FILED JULY 28,1913- 1,212,264. Patented Jan. 16,1917.

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NILS M. ROSENDAHL, OF CHICAGO, ILLINOIS, ASSIGNOR TO FREDERICK C.AUSTIN, OF CHICAGO, ILLINOIS.

SCREENING AND DRYING APPARATUS.

Specification of Letters Patent.

Patented Jan. 16, 1917.

Original application filed January 22, 1913, Serial No. 743,430. Dividedand this application filed July 28,

To all whom it may concern Be it known that I, NILs M. RosENDAHL, acitizen of the United States of America, and resident of Chicago, Cookcounty, Illinois, have invented a certain new and useful Improvement inScreening and Drying Apparatus, of which the following is aspecification.

This is a division of my application No. 743,430, filed January 22,1913, for improvement in machine for making asphaltic or other mixtures.In said prior application, I have made claims for the various featuresand combinations which relate to the handling and mixing of asphalt orother similar materials. In this divisional application I have claimedthe rotary drier or screening apparatus which, although it forms a partof the said machine for making asphalt or other similar mixtures, may beused alone or in conjunction with other machines.

Generally stated, the object of my inven tion is to provide a novel andhighly efficient machine for treating materials, such as gravel and sandand other similar materials which are used, for example, in theconstruction of paving.

More specifically considered, my invention contemplates an improvedscreening apparatus for separating the relatively coarse and lineportions of sand, crushed rock, gravel and other similar materialspreparatory to mixing the same with asphalt or for other purposes.

It is also an object to provide certain details and features ofconstruction and combinations tending to increase the general eificicncyof a rotary drier for this particular purpose, thereby to insure a moresatisfactory street machine for use in laying pavements, and to increasethe eliiciency of a screening apparatus of that particular charactor inwhich a rotary screen is employed for separating the relatively fine andcoarse portions of the sand, gravel or other materials.

To the foregoing and other useful ends, my invention consists in mattershereinafter set forth and claimed.

In the accompanying drawings Figure 1 is a side elevation of a screeningapparatus embodying the principles of my invention, showing the sameemployed as the rotary .drier of an asphalt mixing machine, being SerialNo. 781,460.

necessary in the preparation of asphaltic mixtures for paving, etc., tograde the sand or gravel or crushed rock, and to heat the same, myimproved screening apparatus being especially adapted for heating thematerials while the screening or grading operation is taking place. Fig.2, is a vertical longitudinal section through the structure shown inFig. 1. Fig. 3, is a horizontal section on line 33 in Fig. 2. Fig. 4, isa cross section on line 44 in Fig. 2.

As thus illustrated, the means for preparing the materials, preliminaryto mixing the same together, are as follows: The feeding device Acomprises a hopper a provided with a discharge spout a projecting withinthe machine, said hopper extending transversely of the machine at theend thereof. A transverse and horizontally disposed shaft a is arrangedin the said hopper, and is provided with right and left screws whichfeed the materials to the center of the hopper, and then into the saidspout. From the said spout the materials are delivered to a rotary drumcomprising inner and outer shells b and b the inner shell beingperforated to serve as a screen, and having imperforate end portions 6which rest upon wheels or rollers Z2 which latter are suitably mountedwithin the body C of the machine. The said inner shell 6 is providedwith longitudinal angle-iron ribs 6 having feed blades 6 whereby thematerials are gradually fed forward within the drum, it being observedthat these blades are arranged obliquely relative to the said ribs. Thetwo shells are spaced a distance apart, the outer shell beingimperforate throughout the length thereof, and the said space betweenthe two shells being provided with feed blades 6 whereby the sand andother fine particles which pass through the perforations of the innershell are gradually fed forward. A stationary spout 6 receives therelatively coarse materials, such as crushed rock or stone, from thedelivery end of the drum, the said inner shell being provided withlifting blades for this purpose, said blades carrying the materialsupward and dropping them into said spout. Another spout 6 receives thesand and relatively fine materials from the end of the outer shell. Thetank D overlies the rotary drum, and extends at each side thereof,serving as a sort of housing therefor, space being provided between thedrum and the inner surface of said tank. The top of the tank is providedwith covers or doors (Z Which, when opened, permit of the introductionof asphalt or other similar materials into the tank. The end of the tankis provided with pipe connections d at the bottom thereof, whichconnections are oined to the feed pipe (Z by which the hot asphalt isdelivered to the other end of the machine, as will hereinafter morefully appear.

A plurality of burners E, of any suitable character, are disposed in thereceptacles 6 below the rotary drum, whereby the contents of the saiddrums are heated while the relatively coarse materials are beingseparated from the relatively fine materials. At the same time the heatand products of combustion circulate around and above the rotary drum incontactwith the inner surface of the tank D, whereby the contents ofsaid tank is heated in the required manner. These burners, as shown, areeach constructed from a hollow tile 0 extending transversely of themachine, said tile having its side walls provided with openings 0 forthe escape of the heat and products of combus tion, and its top wallprovided with openings 6 for the same purpose. A gas or oil burner e isprovided at the end of each tile, for producing the heat, it beingunderstood that each tile is preferably constructed from terra cotta,vitreous material, or other suitable heat resisting substance. Steam isconveyed to these burners by pipes 6 laid across the tops of the tilesE, whereby the steam is superheated before entering the burners to forcethe oil or other fuel therefrom. In this way the materials are properlyseparated from each other, and at the same time thoroughly heated whileprogressing 'to the other end of the machine.

From the foregoing, it will be seen that my invention relates moreparticularly to screening and drying apparatus for use in a portablepaving-plant. The apparatus performs a screening function, of course,but the primary object is obviously to dry the materials before theyreach the place where they are to be combined with the hot asphalt. In aportable pavingplant, it is desirable and necessary, of course, that thedifferent instrumentalities be of a character to take up as little roomas possible, and that they be combined in a manner to reduce the entireplant to as small a structure as possible, it being understood thatthese portable pavingplants are hauled along the streets and moved fromplace to place during the progress of paving the streets. The screeningand drying apparatus shown and described is particularly adapted for usein a portable paving-plant, and is designed and constructed with specialreference to its use in conjunction with the other instrumentalitieswhich are necessary in a plant of this kind. Any suitable heating meanscan be employed for heating the materials in the rotary drum of thedrier, but the exterior of the said drum is essentially of a characterto withstand fire for heating the said materials in the desired manner.Consequently, the said drum, including the longitudinal rows of blades 5and 7), becomes very hot, and the backandforth sliding movements of thematerials over the said blades, and on-the longitudinal angle-iron ribs6 as well as on the inner surfaces of the two cylinders, serves veryquickly to dry the materials and raise them to a hightemperature,whereby, when these materials are ready to be combined with asphalt,they are perfectly dry and so hot that they will not cool the asphaltduring the mining operation. The outer cylinder is open at both ends, sothat the hot gases may enter and come into direct contace with thematerials, thus assisting in the drying operation.

That I claim as my invention is:

1. In a portable paving-plant having a machine for treating thematerials, a rotary drum provided with inner and outer walls, said wallsspaced apart, the inner wall being longer than the outer wall andadapted to serve as a screen, the outer wall being imperforate, meansfor feeding materials to one end of said drum, within the said screen,rings on the ends of said screen, supporting rolls engaging said rings,and gearing applied to one end of said screen to rotate the drum, anddevices at the other endof said drum for separately receiving therelatively coarse and fine materials therefrom, said screen havinginterior feed blades for causing the materials to move forward, and feedblades disposed between the said inner and outer walls to move therelatively fine mate rials forward, serving also to support the outerwall.

2. In a portable paving-plant having a machine for treating thematerials, a rotary drum provided with inner and outer walls, said wallsspaced apart, the inner wall being adapted to serve as a screen, theouter wall being imperforate, means for feeding materials to one end ofsaid drum, within the said screen, devices at the other end of said drumfor separately receiving the relatively coarse and fine materialstherefrom, said drum being disposed horizontally, and said inner wallhaving imperforate end portions, means whereby said entire drum issupported by said end portions, and a plurality of parallel series ofblades for supporting the outer wall on the inner wall, serving topropel the materials in the required direction.

3. In a portable paving-plant having a machine for preliminarilytreating the mate rials, a drum mounted to rotate about a hor izontaldisposed axis, having internal longitudinal rows of feed blades, saidblades being disposed at angles oblique to the length of each row, withspace between adjacent rows, thereby to feed the materials from one endto the other of said drum, a cylinder inside of said rows of blades,means to deliver the materials to one end of said drum, mechanismencircling said means to rotate said drum, and means to support saiddrum at the ends thereof.

4. In a portable paving-plant having a machine for preliminarilytreating the materials, a drum mounted to rotate about a horizontallydisposed axis, having internal longitudinal rows of feed blades, saidblades being disposed at angles oblique to the length of each row, withspace between adjacent rows, thereby to feed the materials from one endto the other of said drum, means to deliver the materials to one end ofsaid drum, mechanism to rotate said drum, means to support said drum atthe ends thereof, said drum comprising concentrically arrangedcylinders, and each cylinder having said rows of blades secured to theinner surface thereof, one cylinder feeding to the other, and the outerwall being imperforate and of metal to withstand fire to heat thematerials.

5. In a portable paving-plant having a machine for preliminarilytreating the materials, a drum mounted to rotate about a horizontallydisposed axis, having internal longitudinal rows of feed blades, saidblades being disposed at angles oblique to the length of each row, withspace between adjacent rows, thereby to feed the materials from one endto the other of said drum, a cylinder inside of said rows of blades,means to deliver the materials to one end of said drum, mechanism torotate said drum, and means to support said drum at the ends thereof,said drum having an outer imperforate metal wall adapted to withstandfire to heat the materials.

6. In a portable paving-plant having a machine for treating thematerials, a rotary drum provided with inner and outer walls, said wallsspaced apart, the inner wallbeing larger than the outer wall and adaptedto serve as a screen, the outer wall being imperforate, means forfeeding materials to one end of said drum, within the said screen, ringson the ends of said screen, supporting rolls engaging said rings,gearing applied to one end of said screen to rotate the drum, anddevices at the other end of said drum for separately receiving therelatively coarse and fine materials therefrom, said screen havinginterior feed blades for causing the materials to move forward, and feedblades disposed between the said inner and outer walls to move therelatively fine materials forward, serving also to support the outerwall, said inner wall having means to elevate the coarse materials intoposition to fall into one of said devices, which devices arearranged-one above the other with the end portion of the drumoverhanging the lower device and containing the upper device.

7. In a portable paving-plant having a machine for treating thematerials, a rotary drum provided with inner and outer walls, said wallsspaced apart, the inner wall being adapted to serve as a screen, theouter wall being imperforate, means for feeding materials to one end ofsaid drum, within the said screen, devices at the other end of said drumfor separately receiving the relatively coarse and fine materialstherefrom, said drum being disposed horizontally, and said inner wallhaving imperforate end portions, means whereby said entire drum issupported by said end portions, and a plurality of parallel series ofblades for supporting the outer wall on the inner wall, serving topropel the materials in the required direction, said inner wall havingmeans to elevate the coarse materials into position to fall into one ofsaid devices, which devices are arranged one above the other with theend portion of the drum overhanging the lower device and containing theupper device.

8. In a portable paving-plant having a machine for treating thematerials, a rotary drum provided with inner and outer walls, said wallsspaced apart, the inner wall being larger than the outer wall andadapted. to serve as a screen, the outer wall being imperforate, meansfor feeding materials to one end of said drum, within the said screen,rings on the ends of said screen, supporting rolls engaging said rings,gearing applied to one end of said screen to rotate the drum, devices atthe other end of said drum for separately receiving the relativelycoarse and fine materials therefrom, said screen having interior feedblades for causing the materials to move forward, and feed bladesdisposed between the said inner and outer walls to move the relativelyfine materials forward, serving also to support the outer wall, saidouter wall being a cylinder which is open at opposite ends thereof andshorter than said screen, and angle-irons secured to said screen tosupport the blades therein and form ribs to carry the materials upward adistance.

9. In a portable pavingplant having a machine for treating thematerials, a rotary drum provided with inner and outer walls, said wallsspaced apart, the inner wall being adapted to serve as a screen, theouter wall being imperforate, means for feeding materials to one end ofsaid drum, within the said screen, devices at the other end of said drumfor separately receiving the relatively coarse and fine materialstherefrom, said drum being disposed horizontally, and said inner wallhaving imperforate end portions, means whereby said entire drum issupported by said end portions, a plurality of parallel series of bladesfor supporting the outer wall on the inner wall, serving to propel thematerials in the required direction, said outer wall being a cylinderwhich is open at opposite ends thereof and shorter than said screen, andangle-irons secured to said screen to support the blades therein andform ribs to carry the materials upward a distance.

10. In a portable paving-plant having a machine for treating thematerials, a rotary drum provided with inner and outer walls, said wallsspaced apart, the inner wall being larger than the outer wall andadapted to serve as a screen, the outer wall being imperforate, meansfor feeding materials to one end of said drum, within the said screen,rings on the ends of said screen, supporting rolls engaging said rings,gearing applied to one end of said screen to rotate the drum, devices atthe other end of said drum for separately receiving the relativelycoarse and fine materials therefrom, said screen having interior feedblades for causingthe materials to move forward, and feed bladesdisposed between the said inner and outer walls to move the relativelyfine materials forward, serving also to support the outer wall, meansforming ribs in said screen to carry the materials upward a distance,and means secured to the ends of said ribs to deliver the coarsematerials to one of said devices.

11. In a portable paving-plant having a machine for treating thematerials, a rotary drum provided with inner and outer walls, said wallsspaced apart, the inner wall being adapted to serve as a screen, theouter wall being imperforate, means for feeding materials to one end ofsaid drum, within the said screen, devices at the other end of said drumfor separately receiving the relatively coarse and fine materialstherefrom, said drum being disposed horizontally, and said inner wallhaving imperforate end portions, means whereby said entire drum issupported by said end portions, a plurality of parallel series of bladesfor supporting the outer wall on the inner wall, serving to propel thematerialsin the required direction, means forming ribs in said screen tocarry the materials upward a distance, and means secured to the ends ofsaid ribs to deliver the coarse materials to one of said devices.

12. In a portable paving-plant having a machine for treating thematerials, a rotary drum provided with inner and outer walls, said wallsspaced apart, the inner Wall being larger than the outer wall andadapted to serve as a screen, the outer wall being imperforate, meansfor feeding materials to one end of said drum, within the said screen,rings on the ends of said screen, supporting rolls engaging said rings,gearing applied to one end of said screen to rotate the drum and devicesat the other end of said drum for separately receiving the relativelycoarse and fine materials therefrom, said screen having interior feedblades for causing the materials to move forward, and feed bladesdisposed between the said inner and outer walls to move the relativelyfine materials forward, serving also to support the outer wall, saiddrum having an imperforate outer surface to withstand fire to heat thematerials.

13. In a portable paving-plant having a machine for treating thematerials, a rotary drum provided with inner and outer walls, said wallsspaced apart, the inner, wall being adapted to serve as a screen, theouter wall bein imperforate, means for feeding mate rials to one end ofsaid drum, within the said screen, devices at the other end of said drumfor separately receiving the relatively coarse and fine materialstherefrom, said drum being disposed horizontally, and said inner wallhaving imperforate end portions, means whereby said entire drum issupported by said end portions, and a plurality of parallel series ofblades for supporting the outer wall on the inner wall, serving topropel the materials in the required direcion, said drum having animperforate outer surface to withstand fire to heat the materials.

Signed by me at Chicago, Illinois, this I Qetth day of July 1913.

NILS M. ROSENDAHL. Witnesses J. RICHARDSON, R. E. SEHNEM.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents. Washington, D. C.

